Adequacy of existing house foundations for resisting earthquakes
The cost-benefit of upgrading
The past performance of foundations in earthquakes for timber dwellings prompted a practical investigation into the adequacy of existing sub-floor bracing, connection capacity and the overall adherence to NZS3604:1999. Using information gathered from a sample of 80 Wellington dwellings and by using the results from an Earthquake Loss modeller, it was found that the cost of upgrading “at risk” foundations is almost 30 times less expensive than the complete cost of rebuilding dwellings. Potential damage mitigation saves around 5 times the calculated total damage costs. This saving has the potential to reduce temporary shelter costs and other large unknown costs of post-earthquake rehabilitation and reconstruction.
Adams, R. D., Lensen, G. J., Strachan, C. M. & Laws, H. R. (1970). "Seddon Earthquake, New Zealand, April 1966". DSIR, Wellington, Bulletin 199.
BRANZ (2003). "Lessons from the 1987 Edgecumbe earthquake". BRANZ Bulletin 444. ten Broeke, J. M. (1979). Diploma in building, Case study. Architecture. Wellington, Victoria University of Wellington.
Clark, S., Jones, M. & Page, I. C. (2005). BRANZ Study Report 2005 House Condition Survey. BRANZ Study Report 142. Wellington, BRANZ.
Cooney, R. C. (1982). "Strengthening houses against earthquake: a handbook of remedial measures". BRANZ Technical Paper 37.
Cooney, R. C. & Fowkes, A. H. R. (1981). "New Zealand Houses in Earthquakes- What Will Happen?" BRANZ Reprint Series No. 21, BRANZ, Wellington.
Cousins, J. (2005). Earthquake Loss Modeller. 14 Sep 2005 ed. Wellington, Institute of Geological and Nuclear Sciences Limited.
Davey, R. A. & Shephard, R. B. (1995). "Earthquake risk assessment study : study area 1, Wellington City", Wellington, Works Consultancy Services.
Dixon, C. E. (1931). "Earthquake proves superiority of wooden buildings". New Zealand National Review, pp 45-48.
Hamilton, R. M., Lensen, G. J., Skinner, R. I., Hall, O. J., Andrews, A. L., Strachan, C. M. & Glogau, O. A. (1969). "Gisborne earthquake, New Zealand, March 1966". DSIR, Wellington, Bulletin 194.
Henderson, J. (1937). "The West Nelson earthquakes of 1929 : with notes on the geological structure of West Nelson", Wellington, Government Printer.
Jennings, P. C. & Housner, G. W. (1971). "Engineering features of the San Fernando Earthquake, February 9, 1971. Pasadena, California". California Institute of
Technology, Earthquake Engineering Research Laboratory Report 71-02.
New Zealand State Forest Service, NZSFS (1924). Building conference relating to the use of Timber in building construction. In NZSFS (Ed.), Wellington, Government Printer.
Park, R. (1995). "The Great Hanshin earthquake. Wellington after the ‘Quake : The Challenge of Rebuilding Cities. Wellington, New Zealand", Earthquake Commission and Centre for Advanced Engineering.
Pender, M. J. & Robertson, T. W. (1987). "Edgecombe Earthquake: Reconnaissance Report". Bulletin of the National Society for Earthquake Engineering, 20(3).
Shepherd, R., Bryant, A. H. & Carr, A. J. (1970). "The 1968 Inangahua earthquake". Canterbury Engineering Journal no.1, pp 2-86.
Slade, G. P. (1979). "Domestic Detailing for earthquakes - past and present practice". School of Architecture. Wellington, Victoria University of Wellington.
Standards Association of New Zealand, SANZ (1978). "Code of Practice for light timber frame buildings not requiring specific design", NZS 3604:1978.
Standards Association of New Zealand, SANZ (1992). "Code of Practice for general structural design and design loadings for buildings", NZS 4203:1992.
Standards Association of New Zealand, SANZ (1999). "Code of Practice for light timber frame buildings not requiring specific design", NZS 3604:1999.
Standards Association of New Zealand, SANZ (1944). N.Z.S.S.95 "New Zealand Standard Code of Building Bylaws". Wellington, Government Printer.
Standards Association of New Zealand, SANZ (1964). NZSS 1900 : Chapter 6.1: "Residential buildings".
Copyright (c) 2008 J. D. Irvine, Geoff C. Thomas
This work is licensed under a Creative Commons Attribution 4.0 International License.